Officials urge locals and businesses to cut back on electricity usage to prevent blackouts.

The death toll from a powerful earthquake that hit Japan's Hokkaido Island last week has risen to 44, with 660 others injured.

Around 2,500 people remain in evacuation centres after the tremor on Thursday, according to Japanese officials.

Although electricity to the island has been restored, Japan's trade minister Hiroshige Seko called on both businesses and residents in Hokkaido to use 20 percent less energy to prevent further blackouts.

"It's very important now for all residents, businesses, the government, and electricity suppliers to work together towards this goal of 20 percent energy-saving," Seko told a news conference late on Sunday.

Power outages since the earthquake have hit businesses like Toyota, which over the weekend suspended production at most of its assembly plants.

The company said that it would resume production at its "parts factories" in Hokkaido during night shifts. The factories are responsible for building transmissions and other essential components.

Due to disruptions to its supply chain, Toyota is suspending production at 16 of 18 domestic car-assembly plants and the company says it will fully resume production by Thursday.

Japan is situated in the "Ring of Fire" arc of volcanoes and ocean trenches. The arc accounts for 20 percent of the world's earthquakes of magnitude 6 or greater.